With computer related equipment advanced rapidly, information industry are thriving. The capacity required by software also increases greatly. As a result, the demand for transmission speed of hard disks and computer external electronic devices also grows constantly.
Among the present commercialized transmission products, Universal Serial Bus interface (USB interface for short) and IEEE1394 series products developed by Apple Computer Inc. are the most widely used transmission specifications. In addition to providing signal transmission, they also can provide power supply to an external electronic device. Take the USB interface for instance, each USB interface can provide voltage up to 5 Volts and current up to 500 mA. Hence each USB port can provide 2.5 W of power. However, the present general IDE hard disk of 7200 RPM requires the power of 20 W, a 50×ATAPI CD-ROM requires 10-25 W, a SCSI CD-ROM requires 12 W, a 12×/10×/40×SCSI CD-R/RW requires 20 W, and a 16×ATAPI DVD-ROM requires 10-25 W. Hence the transmission apparatus adopted the present USB interface to provide electricity and signal transmission for hard disks or optical disk drives cannot fully meet the performance requirements of the external products mentioned above. Hence using the USB interface or IEEE1394 series products cannot provide sufficient electric power required. An additional portable transformer has to be prepared to connect the aforesaid external electronic devices. The technique previously discussed has to be upgraded.
Moreover, the new generation of hot-swap SATA hard disk for adopts a new hard disk transmission mode. It is a serial transmission (differs from ATA parallel transmission) at a high frequency (ATA is 33 Mhz, while SATA is 150 Mhz). It also can transmit for a longer distance, consumes less electricity, and uses lower computer power. The hard disk that adopts SATA also has a new power supply mode. As the hard disk consumes less electricity than the ATA type, the temperature is lower. At present SATA on the main stream hard disk still does not fully exhaust ATA transmission speed, its benefits are not fully appreciated. But when the hard disk of a higher speed is developed, its benefits of transmission speed will be significant. In addition to the benefit of higher transmission speed, the SATA transmission line is thinner that the IDE flat cable. The SATA flat cable can reach 100 cm according to the specification. It is more than double the 45 cm of the PATA upper limit. This can improve wiring in the chassis. Moreover, SATA supports plug-and-play function, and is more convenient to couple an external hard disk. However the hard disk or optical disk made according to this specification requires more electric power to reach the original design object.
R.O.C. Patent Publication No. M242774 and No. M245516 disclose a power supply equipped with a power socket to couple with external electronic devices. They can provide sufficient electric power for the external electronic devices. But they cannot provide signal transmission at the same time.
Based on previous discussion, the optimal approach is to provide an apparatus that can integrate power supply and signal transmission, and offer a voltage output required on the external electronic devices. Hence how to directly couple the mainboard and hard disk or external electronic device is an issue remained to be resolved in the industry.